I would definately recommend a visit to Andersonville for those that have not visited. It really shows how horrible the Civil War was. I recall reading about how a Tennessee Unionist who was held at Andersonville responded when a former Confederate veteran was going to be the pastor of his church. This CS veteran happened to serve in the regiment that captured the Union soldier, and his regiment. The Union vet objected to the selection of the pastor, and when told to forgive, he was quoted as saying, "The Lord was only crucified, he never had to spend time in Andersonville!". There are over 700 Tennessee Unionists buried in the Andersonville Cemetery.
Actually, there was another man tried and convicted during the war for war crimes. He was Champ Ferguson, and was a noted guerilla fighter. He was active in the Tennessee/Kentucky area, and was notorious for murdering any Federal soldier he captured, even shooting to death one who was laying in his hospital bed. There is a book that has been recently published about him recently.